Demi Lovato: It Was 'Great' To Work With 'Best Friend' Selena Gomez

Demi Lovato and Selena Gomez's real-life friendship really translates to the small screen. Their movie, "Princess Protection Program," became the third-highest rated movie to debut on the Disney Channel. And, with the DVD of the film being released on Tuesday (June 30), fans can enjoy their onscreen BFF chemistry anytime they want.

Demi explained to MTV News just what their off-screen BFF chemistry is like, saying that opposites attract. "I definitely say what is on my mind, like, right then and there if I have a problem with something."

She went on to explain that in on the rare occasions that they do fight with each other, the girls have very different arguing techniques. "I'll be like, 'Dude, not cool.' And she'll totally take it and be like, 'OK, I'm sorry,' " Lovato offered. "And when we argue, I'm always the one that's like, 'Yo, what's up?' and she's just like, [very calmly] 'You know Demi, I just don't really agree with this.' I'm the one with the attitude. She totally takes it, though."

But most of the time the girls get along quite well and during the making of the "Princess Protection Program," the pair had a lot of time to really bond. "Working with Selena on the movie, it was a ton of fun ... we got to shoot together every day," she said. "We shot in Puerto Rico, so we'd go to the beach on the weekends and it was such a great experience."

And for fans of the teen queens who wonder what friendship is like for them, Demi explains that it's really no different than their fans' relationships. "It's just, like, friendship ... it's great 'cause she's one of my best friends," she said. "We're, like, normal girls."

So what do two normal, famous girls do when they're not making movies together? Play video games, obviously. "We play video games or we will write songs. We'll hang out, just play dress-up and just [watch] scary movies," she said. What's their favorite video game? "Grand Theft Auto. She got me into when we were, like, 8. It was so much fun."